Deluxe Visitor List

    // Deluxe Visitor Log - keeps track of visitors to the region, storing the information in a notecard to preserve
    //                      the data between script resets, region restarts and the like. When touched by the owner,
    //                      produces a notecard containing the visitor list sorted by number of visits, alphabetically
    //                      by visitor name, and by date of first visit. (If anyone other than the owner touches it,
    //                      they are simply told the number of visitors the region has had.)
    //
    // Requires the following OSSL functions: osMakeNotecard(), osGetAgents(), osAvatarName2Key()
    // Make sure they are allowed in OpenSim.ini for the UUID of the avatar owning the object which contains the script.
    //
    // Version 1.0 by Warin Cascabel (4 July 2009)
    // Version 1.1 by Warin Cascabel (6 July 2009) - set object description to visitors/visits info

    //======================================== Variables ========================================

    // ------------------------------ Configuration variables -----------------------------------

    float TimerInterval = 60.0;                // Number of seconds between polling the region for new avatars
    string DataNotecard = "Visitor List Data"; // Name of the notecard in which data is stored


    // ------------------------- Internal variables - do not change -----------------------------

    list     Visitors;      // Data stored in the format [ UUID, Name, Visits [...]]
    list     CurrentlyHere; // UUIDs of avatars detected during the previous scan
    key      DataRequest;   // Used for reading in the settings notecard
    integer  NotecardLine;  // Likewise
    //======================================== Functions ========================================

    // AddName() adds the provided details to the master list, or updates the visit count if the person is
    //           already present in the list.
    //
    integer AddName( string UUID, string Name )
    {
        integer TotalVisits = 1;
        integer IndexPos = llListFindList( Visitors, [ UUID ] ); // Search for the UUID in our master list
        if (IndexPos == -1) // If not found in the list, add them with 1 visit
        {
            Visitors += [ UUID, Name, (string) 1 ];
        }
        else // If they were found in the list, increment their visit count
        {
            integer CountPos = IndexPos + 2;
            TotalVisits = llList2Integer( Visitors, CountPos ) + 1;
            Visitors = llListReplaceList( Visitors, [ (string) TotalVisits ], CountPos, CountPos );
        }
        return 1;
    }


    // CheckNames() gets the list of agents present in the region, ignores any who were present during the last scan,
    //              and adds the remainder to the master list (or increments their visit count if they were already in it)
    //
    CheckNames()
    {
        integer NamesAdded = 0;
        list l = osGetAgents();  // Get the list of all the agents present in the region (better than sensors!)
        list RecentScan;         // To hold the name and UUID of everyone found, but who was not present during last scan
        list RecentUUIDs;        // To hold just the UUIDs of everyone found, but who was not present during last scan
        list AllUUIDsFound;      // To hold the UUIDs of everyone found, regardless of whether or not they were present last time
        integer i = llGetListLength( l ); // general iterator variable
        //
        // First, build a list containing the data of everyone who wasn't found during the previous scan
        //
        while (i--)
        {
            string AvatarName = llList2String( l, i );                     // Get the full name
            list NameParts = llParseString2List( AvatarName, [ " "], [] ); // break it into first and last names
            key UUID = osAvatarName2Key( llList2String( NameParts, 0 ), llList2String( NameParts, 1 )); // Get the UUID
            AllUUIDsFound += [ UUID ];                                     // Add their UUID to the list of all UUIDs found
            if (llListFindList( CurrentlyHere, [ UUID ] ) == -1)           // if we didn't find the person during the previous scan:
            {
                RecentUUIDs += [ UUID ];                                   // Add their UUID to the list of new UUIDs found during this scan
                RecentScan += [ UUID, AvatarName ];                        // Add all their information to the recent scan list
            }
        }
        CurrentlyHere = AllUUIDsFound; // Replace CurrentlyHere with the list of everyone who's present in the region now.
        //
        // Add anyone new from the most recent scan to the master list, or increase their visit counts if they've already been here before
        //
        for (i = llGetListLength( RecentScan ); i > 0; i -= 2)
        {
            string thisUUID = llList2String( RecentScan, i-2 );
            NamesAdded += AddName( thisUUID, llList2String( RecentScan, i-1 ));
        }
        //
        // If we actually did anything, write out a new notecard to save the data.
        //
        if (NamesAdded)
        {
            if (llGetInventoryKey( DataNotecard ) != NULL_KEY) llRemoveInventory( DataNotecard );
            osMakeNotecard( DataNotecard, Visitors );
            llSetObjectDesc( (string) (llGetListLength( Visitors ) / 3) + " visitors / " + (string) CountTotalVisits() + " visits" );
        }
    }


    // CountTotalVisits() returns the total number of visits recorded by all avatars
    //
    integer CountTotalVisits()
    {
        integer RetVal = 0;
        integer i = llGetListLength( Visitors ) - 1;
        for (i = llGetListLength( Visitors ) - 1; i > 0; i -= 3)
        {
            RetVal += llList2Integer( Visitors, i );
        }
        return RetVal;
    }

    // DeliverReportNotecard() builds a notecard containing the visitor list sorted three ways: by frequency of visit (descending),
    //                         alphabetically by visitor name, and by date of first visit. It then delivers the notecard to the
    //                         owner, and deletes it from inventory.
    //
    DeliverReportNotecard()
    {
        list OrderedList;                         // to store the list ordered by date of visit
        list NameList;                            // to store the list ordered by avatar name
        list VisitList;                           // to store the list ordered by visit count
        list Notecard;                            // to store the report notecard
        integer j = llGetListLength( Visitors );
        integer i;
        integer VisitorsLogged = j/3;
        integer VisitsLogged = CountTotalVisits();
        llOwnerSay( (string) (j/3) + " visitors/" + (string) VisitsLogged + " visits logged. Please wait while the full report is generated." );
        for (i = 0; i < j; i += 3)
        {
            string name    = llList2String( Visitors, i+1 );
            integer visits = llList2Integer( Visitors, i+2 );
            string sss     = "s";
            if (visits == 1) sss = "";
            OrderedList += [ llToLower( name ), name + " (" + (string) visits + " visit" + sss + ")" ];
            VisitList += [ visits, (string) visits + " : " + name ];
        }
        if (VisitorsLogged == 1) // OpenSim screws up llList2ListStrided if there's only one stride in the list.
        {
            OrderedList = llDeleteSubList( OrderedList, 0, 0 );
            NameList = OrderedList;
            VisitList = llDeleteSubList( VisitList, 0, 0 );
        }
        else
        {
            NameList = llList2ListStrided( llDeleteSubList( llListSort( OrderedList, 2, TRUE), 0, 0 ), 0, -1, 2 ); // sort alphabetically
            OrderedList = llList2ListStrided( llDeleteSubList( OrderedList, 0, 0 ), 0, -1, 2 );
            VisitList = llListSort( VisitList, 2, FALSE );                                   // sort by descending visit count
            VisitList = llList2ListStrided( llDeleteSubList( VisitList, 0, 0 ), 0, -1, 2 );  // Get only the text to display
        }
        Notecard =  [ "Total visitors: " + (string) VisitorsLogged ];
        Notecard += [ "Total visits: " + (string) VisitsLogged ];
        Notecard += [ "", "Sorted by number of visits: ", "" ] + VisitList;
        Notecard += [ "", "Sorted by name:", "" ] + NameList;
        Notecard += [ "", "Sorted by date of first visit:", "" ] + OrderedList;
        Notecard += [ "", "Total visitors: " + (string) VisitorsLogged ];
        Notecard += [ "Total visits: " + (string) VisitsLogged ];
        string NotecardName = llGetRegionName() + " visitor list : " + llGetTimestamp();
        osMakeNotecard( NotecardName, Notecard );
        llGiveInventory( llGetOwner(), NotecardName );
        llRemoveInventory( NotecardName );

    }

    // ================================ default state handler ==================================

    default {

        state_entry() // Read in the saved visitor list data, if it exists, and switch to the running state.
        {
            Visitors = [];                                                    // clear out the visitors list
            if (llGetInventoryKey( DataNotecard ) == NULL_KEY) state running; // switch to running state if the notecard doesn't exist
            llOwnerSay( "Reading saved visitor list data" );
            NotecardLine = 0;
            DataRequest = llGetNotecardLine( DataNotecard, 0 );
        }

        dataserver( key id, string data )
        {
            if (id != DataRequest) return;
            if (data == EOF)
                state running;
            else
            {
                data = llStringTrim( data, STRING_TRIM );
                if (data != "") Visitors += [ data ];
                DataRequest = llGetNotecardLine( DataNotecard, ++NotecardLine );
            }
        }
    }

    // ================================ running state handler ==================================

    state running
    {
        // state_entry(): load in notecard, if present, set a timer, and check region immediately.
        //
        state_entry()
        {
            llOwnerSay( "Visitor scanning active" );
            llSetTimerEvent( TimerInterval );  // Set the timer for periodic checks
            CheckNames();                      // Check the region immediately for avatars
        }

        // touch_start() will cause the report card to be generated, if the touch was from our
        //               owner; otherwise, it will tell the toucher how many visitors the region
        //               has logged.
        //
        touch_start( integer foo )
        {
            if (llDetectedKey( 0 ) == llGetOwner()) // being lazy, and assuming there's only one touch.
                DeliverReportNotecard();
            else
                llInstantMessage( llDetectedKey( 0 ), (string) (llGetListLength( Visitors ) / 3) + " visitor(s) logged, with a total of " + (string) CountTotalVisits() + " visits." );
        }

        // Poll the region every x seconds (as configured by the TimerInterval variable). Rather than using
        // sensors, which are limited both in range and in the number of avatars they can detect, we'll use
        // the OpenSim-only function osGetAgents().
        //
        timer()
        {
            CheckNames();
        }

        // Reset the script if the region has restarted. This mainly restarts the timer and clears out the list
        // of people who were detected the last time the region was scanned, but it's good to avoid any other
        // unforeseen consequences.
        //
        changed( integer whatChanged )
        {
            if (whatChanged & 256) llResetScript();
        }
    }